Two-effect titanium liquid concentration device and concentration process

Abstract

The invention discloses a two-effect titanium liquid concentration device and a concentration process. The concentration device comprises a preheater, a primary heat exchanger, a secondary heat exchanger, a flash tank, a film evaporator and an atmospheric condenser, wherein a solution outlet of the preheater is connected with a solution inlet of the primary heat exchanger; a solution outlet of the primary heat exchanger is connected with a solution inlet of the secondary heat exchanger by virtue of a circulating pump; a solution outlet of the secondary heat exchanger is connected with a solution inlet of the flash tank; a steam outlet of the flash tank is connected with a steam inlet of the preheater; a steam outlet of the preheater is connected to a first steam inlet of the condenser; a first solution outlet of the flash tank is connected with a solution inlet of the primary heat exchanger; and a second solution outlet of the flash tank is connected with a solution inlet of the film evaporator. According to the concentration device disclosed by the invention, the flow velocity of titanium liquid in the primary heat exchanger and the secondary heat exchanger is controlled by virtue of the circulating pump, the problem of scaling and blockage of heat exchange tubes in the heat exchangers in large area is solved, the total heat transfer coefficient of the heat exchangers is greatly improved, and the heat exchange area of the heat exchangers is reduced.

Description

technical field [0001] The invention relates to the technical field of titanium liquid concentration, in particular to a titanium liquid two-effect concentration device and a concentration process. Background technique [0002] In the industrial production of sulfuric acid titanium dioxide, it is necessary to concentrate the dilute titanium solution of 150g / L (mass concentration of titanium dioxide) to 220g / L, which is usually evaporated by a single-effect rising film evaporator, and the steam consumption of this evaporation device is relatively high. Using a multi-effect evaporation device is one of the effective ways to reduce the consumption of steam in the titanium liquid concentration process. The common method of multi-effect concentration is the second-effect vacuum flash concentration. The second effect in the process uses the secondary steam from the first-effect flash evaporation as the heat source. The temperature of the secondary steam is 60~65°C. Due to the ...

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Problems solved by technology

[0002] In the industrial production of sulfuric acid titanium dioxide, it is necessary to concentrate 150g / L (mass concentration of titanium dioxide) of dilute titanium solution to 220g / L, which is usually evaporated by a single-effect rising film evaporator, and the steam consumption of this evaporation device is relatively high

Using a multi-effect evaporation device is one of the effective ways to reduce the consumption of steam in the titanium liquid concentration process. The common method of multi-effect concentration is the second-effect vacuum flash concentration. The second effect in the process uses the secondary steam from the first-effect flash evaporation as the heat source. The temperature of the secondary steam is 60~65°C. Due to the low temperature, the heat exchange area of ​​the heat exchanger required for the second effect is relatively large. At the same time, because the titanium liquid contains a large amount of metal calcium ions, it is easy to form calcium sulfate or gypsum solids during the concentration process. Precipitation, deposited on the surface of heat exchange tubes to form scale, affecting heat exchange efficiency

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